WinShowViewStrategyBase.WinWindowShowing Event

Occurs before a WinWindow is displayed.

Namespace: DevExpress.ExpressApp.Win

Assembly: DevExpress.ExpressApp.Win.v23.2.dll

NuGet Packages: DevExpress.ExpressApp.Win, DevExpress.ExpressApp.Win.Design

NuGet Package: DevExpress.ExpressApp.Win

Declaration

C#

public event EventHandler<WinWindowShowingEventArgs> WinWindowShowing

VB.NET

Public Event WinWindowShowing As EventHandler(Of WinWindowShowingEventArgs)

Event Data

The WinWindowShowing event's data class is WinWindowShowingEventArgs. The following properties provide information specific to this event:

Property	Description
Form	Gets the Form to be displayed.
IsModal	Gets a value indicating whether or not the WinWindowShowingEventArgs.Form is displayed modally.
Window	Gets a WinWindow to be displayed.

Remarks

Handle the WinWindowShowing event to access the Form passed using the WinWindowShowingEventArgs.Form parameter. You can also access the WinWindowShowingEventArgs.IsModal parameter to determine if the form is modal. As the Show View Strategy can be changed during the application life cycle, it s recommended to subscribe to the WinWindowShowing event from the XafApplication.ShowViewStrategyChanged event handler. In the snippet bellow, the main window is adjusted to be shown at the (10, 10) point, the modal window is adjusted to be shown at the center of the active form and all other forms are adjusted to be shown at the active form location.

C#

using System.Drawing;
// ...
static void Main() {
    // ...
    MySolutionWindowsFormsApplication winApplication = new MySolutionWindowsFormsApplication ();
    // ...
    winApplication.ShowViewStrategyChanged += WinApplication_ShowViewStrategyChanged;
    // ...
    winApplication.Setup();
    winApplication.Start();
}
private static void WinApplication_ShowViewStrategyChanged(object sender, EventArgs e) {
    WinApplication winApplication = (WinApplication)sender;
    if (winApplication.ShowViewStrategy != null) {
        winApplication.ShowViewStrategy.WinWindowShowing += ShowViewStrategy_WinWindowShowing;
    }
}
private static void ShowViewStrategy_WinWindowShowing(object sender, WinWindowShowingEventArgs e) {
    if (((WinShowViewStrategyBase)sender).MainWindow == null) {
        e.Form.StartPosition = FormStartPosition.Manual;
        e.Form.Location = new Point(10, 10);
    }
    else {
        if (e.IsModal) {
            e.Form.Owner = Form.ActiveForm;
            e.Form.StartPosition = FormStartPosition.CenterParent;
        }
        else {
            e.Form.StartPosition = FormStartPosition.Manual;
            e.Form.Location = (Form.ActiveForm != null) ? Form.ActiveForm.Location : new Point(10, 10);
        }
    }
}

VB.NET

Imports System.Drawing
' ...
Shared Sub Main()
    ' ...
    Dim winApplication As New MySolutionWindowsFormsApplication()
    ' ...
    AddHandler winApplication.ShowViewStrategyChanged, AddressOf WinApplication_ShowViewStrategyChanged
    ' ...
         winApplication.Setup()
    winApplication.Start()
End Sub
Private Shared Sub WinApplication_ShowViewStrategyChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim winApplication As WinApplication = CType(sender, WinApplication)
    If winApplication.ShowViewStrategy IsNot Nothing Then
        AddHandler winApplication.ShowViewStrategy.WinWindowShowing, AddressOf ShowViewStrategy_WinWindowShowing
    End If
End Sub
Private Shared Sub ShowViewStrategy_WinWindowShowing(ByVal sender As Object, ByVal e As WinWindowShowingEventArgs)
    If (CType(sender, WinShowViewStrategyBase)).MainWindow Is Nothing Then
        e.Form.StartPosition = FormStartPosition.Manual
        e.Form.Location = New Point(10, 10)
    Else
        If e.IsModal Then
            e.Form.Owner = Form.ActiveForm
            e.Form.StartPosition = FormStartPosition.CenterParent
        Else
            e.Form.StartPosition = FormStartPosition.Manual
            e.Form.Location = If((Form.ActiveForm IsNot Nothing), Form.ActiveForm.Location, New Point(10, 10))
        End If
    End If
End Sub